:root {
  --font-sans: system-ui, -apple-system, "Segoe UI", Roboto, helvetica, arial, sans-serif;
  --font-serif: "Source Han Serif", georgia, cambria, "Times New Roman", times, serif;
  --font-mono: "Fira Code", menlo, monaco, consolas, "Liberation Mono", "Courier New", monospace;
  --body-width: 45em;
  --body-bg: #f3f2ee;
  --body-color: #1f0909;
  --border: #c9cbc6;
  --block-bg: #edece8;
  --link-color: #228be6;
}

body {
  margin: 0 auto;
  padding: 3em 2.5em;
  max-width: var(--body-width);
  background: var(--body-bg);
  color: var(--body-color);
  font-size: 16px;
  line-height: 1.75;
  font-weight: 400;
  font-family: var(--font-serif);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  line-height: 1.2;
}

h1 {
  padding-bottom: 0.5em;
  border-bottom: 1px solid var(--border);
  font-size: 2.5em;
}

h2 {
  font-size: 2em;
}

h3 {
  font-size: 1.75em;
}

h4 {
  font-size: 1.5em;
}

h5 {
  font-size: 1.25em;
}

h6 {
  font-size: 1em;
}

hr {
  border: 0;
  height: 1px;
  background: var(--border);
}

ul,
ol {
  position: relative;
  padding-left: 2.5em;
}

li ol > li {
  list-style-type: lower-alpha;
}

li li ol > li {
  list-style-type: lower-roman;
}

/* li > input[type='checkbox'] {
  position: absolute;
  left: 13px;
} */

table {
  margin: 1em 0;
  border-collapse: collapse;
  overflow: auto;
  width: 100%;
}

thead {
  background: var(--border);
  text-align: left;
}

tr:nth-of-type(2n) {
  background: var(--block-bg);
}

th,
td {
  padding: 0.25em 0.5em;
}

blockquote {
  margin: 0;
  padding: 1em 1.25em;
  border-left: 5px solid var(--border);
  background: var(--block-bg);
}

blockquote > :last-child {
  margin-bottom: 0;
}

blockquote > :first-child {
  margin-top: 0;
}

blockquote ul,
blockquote ol {
  padding-left: 1.5em;
}

pre {
  background: var(--block-bg);
}

code {
  font-size: 87.5%;
  font-family: var(--font-mono);
}

pre code {
  display: block;
  padding: 1em 1.25em;
  overflow: auto;
}

img {
  max-width: 100%;
}

a {
  color: var(--link-color);
  text-decoration: none;
}

a:hover,
a:active {
  text-decoration: underline;
}

.sign {
  margin: 4em 0 0;
  padding: 3em 1em;
  border-top: 1px solid #e0e0e0;
  font-size: 0.875em;
  text-align: center;
  opacity: 0.85;
}

.sign i {
  font-style: normal;
  color: #f00;
}